Abstract
Keywords: vehicle safety, sled test, side impact, crash simulation, virtual development
Increasing demands for reduced development costs and timeframes have resulted in a growing need for numerical simulations to facilitate the vehicle development process. The use of simulations is shifting towards the early design phases, a practice also known as "frontloading." This reduces the need for expensive, full vehicle prototypes. In order to realise a virtual side impact development a new process has been developed (1). Within this development process the simulation models are verified with tests of growing complexity from component up to full vehicle system level. The key issue of this verification procedure is a novel sled test rig that enables the replication of a full vehicle side impact test (4), (5).
This sled test rig can be distinguished from state-of-the-art sled test rigs (2), (3) by its conception of primarily providing data for verification of the numerical occupant simulation rather than providing test results that prove the side impact performance of the car. Therefore, the main focus lies in a design that results in minimum effort and need for pretests, a high repeatability of the impact acceleration profiles, high flexibility for change of the test set-up and minimum test costs.
The sled test rig consists of the following components: main sled (representing the full vehicle assembly), door sled (carrying the intruding car side structure) and seat sled (allowing a lateral seat motion). The functionality and components are discussed in detail. Additionally, the work-flow of the validation of the virtual engineering process is explained: Firstly, the results of a numerical finite element (FEM) simulation of a full vehicle side impact are compared to a numerical FEM simulation of the sled test rig. Parameters of the sled test simulation set-up are adjusted until kinematics and dummy injury responses match the full vehicle simulation. Afterwards, the parameters of the numerical sled simulation are directly transferred to the physical test set-up and the test is performed. A sufficient accordance between simulation and test verifies the full vehicle simulation otherwise it has to be reworked.